1. Field of the Invention
The present invention relates to a stress-detection semiconductor device, more particularly, to a stress-detection semiconductor device having a stress detection circuit for detecting electrostatic stress applied to a product semiconductor device during each production process.
2. Description of the Related Art
Due to the progress made in the miniaturization of semiconductor devices and semiconductor elements, such a semiconductor device is now formed as a large scale integration device, and accordingly a PN-junction of the semiconductor element and a gate insulation film of a metal insulation silicon (MIS) transistor are easily destroyed by electric or mechanical stress imposed during the production processes thereof. For example, electrostatic stress (i.e., electro-static discharge: ESD) is applied to the semiconductor device (product semiconductor device) while the semiconductor device is produced, tested, transferred, and therefore, the product semiconductor device sometimes must be scrapped.
Usually, the semiconductor device is checked by carrying out a DC test and a functional test, and these DC and functional tests are carried out in both the wafer state and packaged state of the semiconductor device. Note, the DC test, for example, is carried out by measuring a short-circuit between a power supply terminal and the ground and a leak current among input and output terminals, and the functional test is carried out by measuring various functions when the semiconductor device is in an operational state.
Therefore, the results of the DC test and functional test show that a portion of the semiconductor device is defective, it can be determined whether the defective portion of the semiconductor appeared during the wafer state (i.e., wafer process) or the packaged state (i.e., packaging or assembling process).
Nevertheless, the cause of the appearance of the defective portion of the semiconductor device can not be determined, and in which process the defective portion of the semiconductor device appeared cannot be concretely determined. Namely, in the prior art, for example, when the semiconductor device is destroyed by electrostatic stress, it cannot be determined when or where the electrostatic stress was applied to the semiconductor device.
Consequently, considerable time is required to determine an inferior portion of the design of the semiconductor device and of the manufacturing devices used for carrying out the various production processes of the semiconductor device (i.e., product semiconductor device). Further, this makes it difficult to improve the design of and the device used for manufacturing the product semiconductor device.